Explanation:
sự xuất bản hóa học nào? có một câu hỏi về khoa học mà bạn cần giúp đỡ? tôi luôn ở đây để giúp đỡ!
Answer:
see notes below
Explanation:
The mole is the mass of substance containing 1 Avogadro's Number of particles. That is, 1 mole substance = 1 formula weight. For elements, 1 mole weight is equal to the atomic weight expressed as grams. For molecules, 1 mole weight is equal to the molecular weight expressed as grams.
1 mole = 1 formula weight
<u>Moles to Grams and Grams to Moles</u>
Grams => Moles
Given grams, moles = mass given / formula weight
*Ask the question => How many formula weights are there in the given mass? => Results is always moles.
Moles => Grams
Given moles, grams = moles given X formula weight
*Summary
Grams to Moles => divide by formula weight
Moles to Grams => multiply by formula weight
The Lithium-ion Battery Problem
Overheating. They overheat and explode if charged too fast.
Short life time. They die after less than 1,000 charge/discharge cycles.
Flammable. They use chemicals that are flammable. ...
Toxic. ...
Underperform in extreme temperatures. ...
Expensive casing. ...
Expensive to transport.
Answer:
<h3>The answer is 2 g/cm³</h3>
Explanation:
The density of a substance can be found by using the formula
From the question
mass = 48 g
volume = 24 cm³
We have
We have the final answer as
<h3>2 g/cm³</h3>
Hope this helps you
Answer:
Be (899 kj/mol) , Se (940.9 kj/mol), Ne(2081 kj/mol), He (2370 kj/mol),
Explanation:
For noble gases as they have complete octet so they require high amount of energy to remove the electron.
Trend along period:
As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.
Trend along group:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.
